This is a safety issue

[chermac01]

My motor issues with my 73 Johnson 115 have changed. I have worked out all the problems with the carbs and the floats and I have gotten it to run great with some minor tweaking of the idle speed(it was trying to idle way to slow). Now a new issue has presented itself one that I or the previous owner have ever had an issue with. The motor was Idling at around 700 rpm and it was running great when I went to shut the motor off and the darn thing didn't stop. Now I don't know what has malfunctioned or why this has happened. One would think that if there was an issue with the control it would fault and kill the motor. I am lost and frustrated because I have finally gotten the motor to run well and now I don't know if I can trust it to shut off when I want it to!

 

[F_R]

Re: This is a safety issue

there is a black with yellow stripe wire going from the power pack to the key switch. The key switch grounds that wire to stop the motor. If that wire is broken or disconnected, it won't turn off. Or if the key switch is bad it won't ground the wire and it won't stop. Or if the ground wire is broken or disconnected, same thing. Or if the kill circuit within the power pack......

Anyway, identify the black/yellow wire at the power pack. Simply use a jumper to ground that power pack terminal while it is running and the motor will stop. If it does, troubleshoot the wire to the key switch, the switch, and the ground. However, if the test didn't kill the motor, bad power pack.

 

[WernerF]

Re: This is a safety issue

But be careful, there is a peak voltage of 300V on ther black/yellow wire when the motor is running.

 

[chermac01]

Re: This is a safety issue

Alright this just keeps getting worse for me. I went out this morning and tried to start the motor and the starter was doing a slow turn. The battery is new and fully charged so what the heck is going on here. I jumped the starter and it spun at normal speed so do I have a bad ground somewhere as when the starter turns slow it was smoking right away. When I hook up the battery charger and check the battery with it as soon as I turn the key the battery goes from 16 volts to 13 and then when I try to turn it over the starter absolutely drains the battery from 13 volts to around 10. I did fix the engine cut off, turns out the wire had somehow come loose inside the control.

 

[metriccrescentwrench]

Re: This is a safety issue

In addition to a bad ground there could be a bad connection on the +12 side, bad solenoid, or corroded battery cable. It's not really difficult to figure out, have someone crank the starter for a few seconds and measure the voltage from the + battery terminal to the + hot side of the solenoid, across the solenoid, from the solenoid to starter, from the negative battery terminal to the engine ground, ..... I can't recall the exact voltage drops called out in the manual, but in general none of these measurements WHILE CRANKING should be more than about a volt.

 

[chermac01]

Re: This is a safety issue

So what does it mean when both battery terminals get hot to the point of melting the terminal covers when I crank the motor?

 

[sschefer]

Re: This is a safety issue

It means that the reason your motor kept running was because your carbs were way too lean and you seriously overheated the engine. Probably melted the top edges off the pistons and stuck the rings. Pull a plug and have a look. I'd bet the plugs are covered with aluminum. Sorry, probably not what you wanted to hear.

 

[chermac01]

Re: This is a safety issue

It means that the reason your motor kept running was because your carbs were way too lean and you seriously overheated the engine. Probably melted the top edges off the pistons and stuck the rings. Pull a plug and have a look. I'd bet the plugs are covered with aluminum. Sorry, probably not what you wanted to hear.

Well I checked each cylinder and there was nothing outta the norm. Also I can still turn the motor at the prop with motor in gear

 

[Faztbullet]

Re: This is a safety issue

The starter is drawing to much amperage due to bad cables,bad ground or bad starter. Thats a old field and frame starter and I would ditch it for the newer magnetic starter.

 

[Bob_VT]

Re: This is a safety issue

So what does it mean when both battery terminals get hot to the point of melting the terminal covers when I crank the motor?

Check your battery cables. It can be caused by corrosion inside the cables and I have seen the heating situation before.

The cables corrode inside and create a tremendous amount of resistance. I replaced bot the + and - on my V-4 due to internal corrosion............ and the cables "looked" normal on the outside.

 

[F_R]

Re: This is a safety issue

So what does it mean when both battery terminals get hot to the point of melting the terminal covers when I crank the motor?

Fer cryin' out loud, already. Battery terminals get hot because resistance generates heat. Resistance comes from poor connection. Remove those cables from the battery and clean them shiny bright. Don't just look at them, clean them shiny bright. And make sure they are tight when you put them back together.

Now about that battery: Take it someplace like Auto Zone and have it load tested. They'll do it free. Dropping to 10V while cranking is a symptom of a dead cell. Even new ones can deveop a dead cell, that's why they carry a warranty.

EDIT: You mentioned the starter smoking. That could mean the starter is shorted, or it could mean the engine turns too hard. Either way, it would cause the battery cables to get hot--not just at the battery, but the whole length.

If the simple steps I mentined don't work, you will have to learn to do some voltage drop tests. Don't just start replacing stuff, test it.

 

[CoffeeHound]

Re: This is a safety issue

Right On F-R
Why others don"t read the problem ,, get a coffee , and Think a moment !!

If I am not mistaken :: Starters are made to run only 10 sec. on, and 1 min cool down -- that is what the book here says.
To bubbleeee a terminal takes about 20 sec of continious cranking depending on terminal conditions..
I suspect most don't know it only takes 15 sec.or less toast a weak starter and weak starts are caused by overheating !!

CoffeeHound

 

[Silvertip]

Re: This is a safety issue

And don;t just check the battery end of the cables. The engine end of the battery cables need the same attention. Also look at the cable ends where the cable enters the terminal. Any swelling or corrosion is a sign the ends or the cable need replacing. Use one jumper cable connected to the POS battery terminal. Then touch the other end directly to the starter terminal. If the starter now spins normally you DO NOT have a starter issue.

 

[toddschubert]

Re: This is a safety issue

can you turn flywheel by hand?

 

[chermac01]

Re: This is a safety issue

can you turn flywheel by hand?

yes

 

[emdsapmgr]

Re: This is a safety issue

You said the starter cranks normally when jumped with a fresh battery. That's a good test and indicates the starter should be ok. If the starter still turns slowly with the key switch, you could have a defective starter solenoid. When these solenoids get old, the contacts inside burn and won't transfer current properly. (the starter might crank slowly.) Worse, sometimes the solenoid contacts stick closed, causing massive current draw that can heat up the cables.

 

[chermac01]

Re: This is a safety issue

Replaced the battery cables and now the starter turns normally.